1. Field of the Invention
This invention relates to an internal combustion engine and the pollutant emission control system therefor and in particular to the pollutant emission control system for an internal combustion engine and the combined electric switch and temperature responsive valve of the pollutant emission control system therefor.
2. Description of the Prior Art
In the past it has been conventional to provide various types of temperature responsive valves for controlling the emission of noxious pollutants from an internal combustion engine during its operation. A temperature responsive valve is connected to the coolant system of the internal combustion engine and to the spark advance control of the engine for minimizing the emission of pollutants from the engine during its operation at more than one temperature level. In addition, the temperature responsive valve has included an electric control switch combined therewith for also controlling another portion of the internal combustion engine such as the position of the carburetor butterfly valve thereof during its operation so as to further minimize the emission of pollutants from the engine.
The prior art, as exemplified by U.S. Pats. No. 3,212,337, No. 3,400,698, No. 3,680,533, No. 3,735,334 and No. 3,789,811 illustrates a variety of pollutant emission control devices or apparatus for controlling the emission of pollutants from an internal combustion engine during its use.
One of the problems associated with the prior pollutant emission control apparatus for an internal combustion engine is that they will not satisfactorily meet the requirements of pollution control laws in various countries that are or will become effective. While these air pollution control apparatus may have been satisfactory for the purpose for which they were designed they are not only incapable of meeting the current requirements of the pollution control laws but also are incapable of minimizing the emission of noxious air pollutants in the improved manner comtemplated by the pollutant emission control system of the present invention.